Grinding machine



J. D. @GMW mw GRINDING MACHINE Filed Jan. 16, 1929 Sheets-Sheet 2 Patented May 3, 1932 UNITED STATES PATENT Ior-Flcla JOSEPH DYSON SGAIFE, OF NOTTINGHAMSHIRE, ENGLANDASSIGNORITO THE HEALD MACHINE COMPANY, OF WORCESTER, MASSACHUSETTS, A CORPORATION 0F MASSA- CHUSETTS GRINDING MACHINE Application med January 16,1929, serial Na. 332,859, and inermi mmm member 1a,I 192s.

The present invention relates to grinding machines, particularly to that type known as oscillating raceway grinding machines. In such machines the work piece is continuously rotated upon its own axis andis at the same time swung or oscillated through an arc of a circle about an axis which-in the case of a ball race-is arranged to be tangential to the locus of the centre of curvature of radial sections of the raceway to be ground and is perpendicular to the plane of contact between wheel and work piece which contains the center of the wheel; whilst the grinding wheel itself is rapidly rotated upon its axis and is so mounted as to be capable of being moved into and out of engagement with the work piece to effect grinding thereof.

In such machines the grinding wheel is usually fed in cutting relation to the work piece manually or by a cam arrangement. In the former case it is extremely diicult to produce an entirely accurately ground work piece, and in the latter' case it is necessary to pre-form a suitable cam, and this is by no means a simple matter. Moreover even should the cam be accurately made to pro duce the desired effect its contour will almost certainly vary during use.

rIhe chief object of the present invention therefore is to provide amachine of this kind in which the grinding wheel or the like is positively fed in cutting relation to the work piece in an improved manner.

A further object of the present invention' is to provide a grinding machine of the kind referred to, in which sucessive work pieces ground with great precision may be produced without replacement of the grinding wheel, and without the inconvenience incidental to renewing the grinding wheel and resetting the machine for each work piece to be ground.

A further object of the present invention is to provide a grinding machine of the kind referred to in which a predetermined rela tive movement may be imparted between the workpiece and the grinding wheel lto compensate for Wear or the like on the grinding wheel.

Another object of the present invention is to provide a grinding machine of the kind referred to in which the 'reduction of the` grinding wheel from wear or 'the like, incil dental to a grinding sated for automatically. A

A still further object of the invention is to provide means for truing the grindin wheel after each grinding operation,Y suc means being preferably brought into operation automatically duringl setting up of a' fresh work piece in the machine.

In order that the invention may be more clearly understood and readily` carried into effect reference may now'be had to the accompanying drawings which illustrate the invention by way of example,r and in which Fig. 1 is a front elevation of'a grinding machine constructed according to the invention, part of the base of the machine being broken away in order to more clearly show the operation of certain mechanism, and the truing mechanism being omitted from this' view.

Fig. 2 is a plan view of the machine.

Fig. 3 is a fragmentary rear elevation on an enlarged scale, showing the mechanism for bringing the truing device into truing position.

Fig. 4: is a fragmentary elevation of the truina: mechanism as seen from the left hand end of the machine. the parts being shown on the same scale as Fig. 3.

Fig. 5 is an isometric view of the actuating mechanism for lmoving the wheel in cutting relation to the work, these parts being shown as detached from the machine.

Fig. 6 is a sectional view taken on the line 6 6 of Fig. 1.

Like reference characters refer to like parts throughout the drawings.

Referring first Vto Figures 1, 2, and 6 of the accompanying drawings, the reference numeral 1 indicates the work head or head stock. The'head 1 provides journals for va horizontally disposed rotatable shaft 2. The head is carried by a platform 3 adaptedfor oscillatory movement about a vertical axis 4. For this purpose the platform 3 has a shaft 5 associated therewith either integrally or otherwise. said shaft being rotatably mounted in suitable bearings such as ball bearings operation, is compen- 6 mounted on the machine frame. Suitable slides 7 and 8, preferably disposed at right angles to one another, are provided upon the platform 3, so as to permit thehorizontally disposed shaft 2 to be moved into anyde sired position. The shaft 2 is provided at one end with a face plate 9 to which the work piece may be secured in any desired manner, and also has a pulley 10 mounted thereon to accommodate a driving belt, not shown, whereby the shaft may be rotated.

At the right hand side of the machine as viewed in Figures 1 and 2 is a slide or carrier 11, which is mounted upon the machine frame or bed in such a manner that it is adapted to be moved in a horizontal plane longitudinally of the machine towards and away from the head 1. For this purpose the carrier 11 may be provided with suitable guiding means between itself and the machine frame, and also with a rack 12 co-operating with a gear 13 suitably mounted upon the machine frame, the gear being adapted to be rotated by means, for example, of the handle 14 and at tached pinion 14' to cause movement of the carrier 11 with respect to the frame.

Various 'elements and mechanisms are mounted upon the carrier 11 and these will now be described in detail. Firstly there is a slide 15adapted for movement transversely of the machine frame. Referring toFigs. 1. 2 and 5 movement may be imparted to the slide 15 by a connecting rod 16 which is pivotally connected to a portion 17 provided by the slide at one end 18, and which is pivotally connected at its other end to an element Referring now to Figs. 2 and 5. the driving mechanism for the element 20a which is shown as a disc, is generally designated by the numeral 19. The element 20a is adapted to be rotated manually from a handle 21 associated with a hand wheel 21a, or by power from a pair of stepped pulleys 22a and 226, the former of which is driven at a constant speed from any suitable source of power.- By selecting appropriate opposite grooves in the stepped pulleys 22a and 226' for a connecting belt, not shown, various speeds may be imparted to a shaft 19a which is detachably secured to the pu1ley22b by means of *a clutch 22e. The shaft 19a has a'worm 196 fastened thereto which drives a worm wheel 19e, and the latter is fastened to a shaft 19d and provides also a worm 19e. which is in mesh with a large worm wheel 19;' that is mounted on the same shaft 19g as the element 20a. Likewise fastened to the shaft 19g is a worm wheel 2lb which is in mesh with aworm 210 on a shaft 21d to which is fastened the hand wheel 21a. The worms 19?), 19e and 21e are of steep pitch so that they will either drive the various worm wheels with which they are in mesh, or be driven therefrom. v

The connection 2O between the element 20a and the connecting rod 16 is eccentric to the axis ofv.revolution of the element 20a,

crank, the throw/of which determines the movement ogfffthe slide 15 as the element 20a is rotated. y

Upon the slide 15 and also adaptedfor movement transversely ofthe machine with respect to the slide 15 is mounted a slide 23 which carries a suitable journal 24 for a horizontally disposed grinding wheelshaft 25 which is adapted to be rapidly rotated in any convenient manner for example by means of belting applied to the pulley 25a.

At one end the slide 23 has associated therewith mechanism-shown in Figs. l and 2--by means of which it may be moved transversely of the machine frame relatively to the slide 15. This mechanism may comprise a ratchet wheel 26 mounted upon a shaft 27 journalled in an element 28 attached to the slide 23, said shaft beingV provided with a screw thread adapted to mesh with a co-operating nut element 29 associated with the slide 15 in such a manner that rotation of the shaft 27 causes corresponding movement of the slide 23. Aifinger 30 is mounted upon an arm 31 rockably mounted upon the -`shaft 27 andis adapted to co-operate with an iuclined surface or cam 32 mounted upon the machine frame duringI movement of the carrier 11 longitudinally of the machine. The arm 31 also carries a pawl or pawls 33 adapted to co-operate with the teeth of the ratchet wheel 26 to cause rotation thereof, and consequently of the shaft 27, to move the slide 23 with respect to the slide 15 as and for a purpose which will be explained hereinafter. y

According to the invention the improved machine is provided with mechanism for truing the-peripheral surface of the grinding wheel or the like while a fresh workpiece is being set up in the machine, and this mechanism mayif desired be brought into and thrown out of operation automatically duringmovement of the carrier longitudinally of the machine. vI will now proceed to de-v scribe one form of truing device which may be used but it is to beunderstood that any other suitable device may be'employed.

As shown in Figs. 3 and 4 a pin or projection 34 is attached to the machine frame at the rear thereof with it'a pair of arms 35 of a bell crank lever 36, pivotally mounted at 37 upon the .carrier 11, co-operate. The end of p the bell crank lever 36 opposite the arms' 35 (which are in parallel relation) is connected by means of a rod 39 to an arm 40, the connections 38 and 33a'.v being universal joints. The arm 40 is attached to a support or arm 43 for a diamond or like truing device 44, all these parts being journalled at 41 in a stand ard 42 carried by the slide or carrier 11. It

will thus be seen that movement of the outer end of arm causes corresponding movement of the outer end of arm 43 of the truing device 44, to swing the truing device 44 up and down about the axis 41.

The truing device 44 is mounted in a suitable holder 45 which is journalled in a bearing portion 46 provided by the arm 43, so that the truing device 44 may be oscillated." That portion of the holder 45 lwhich contains the diamond or other truing device is offset from 'the axis of oscillation of the holder, so that the point of the diamond may face the center of oscillation. In order to oscillate the holder 45 about its axis 47, the arm 43 supports a suitable prime mover, such as a P elton water motor 48. Upon the shaft 49l ofthe Pelton motor 48 is a worm 50, which meshes with a worm wheel 51 that is rotatably mounted upon an extension of the arm 43. Attached to the top of the worm wheel 51 is a pin V52, and a link or arm 53 connects this pin to a pin or lug 54 provided by the holder 45. Rotation of the wheel 51 therefore causes oscillation of the holder 45 about the axis 47. The water or other elastic fluid for the Pelton wheel 48 is supplied by means of a flexible pipe 55 and a valve 56' for the water is oper,- ated in anyconvenient manner which may be automatic if desired to ensure that iuid is supplied thereto only at the requisite times.

For the purpose of imparting oscillatory movement to the headstock 1 the vertical shaft 5 has rfastened thereto a suit-able arm 5a, shown in Fig. 2 as extending from a split collar 5?), and the arm 5a. is connected by means of a link rod 57 with a crank oi" the like 585 which'is mounted ony the top of a shaft 58d. Shaft 58a is suitablyjournalled in the machine and received inside of a sleeve 585. See Fig. 1. On the bottom fof the shaft 58a is keyed a movable collar 580, the top portion of whichv fifi consists of a clutch element for engagement with corresponding clutcht-eeth provided by the sleeve 585. Fastened to the sleeve 585v and surrounding it is a worm wheel 58d which meshes with a worm 59a on the end of a shaft 59. The outer end of the shaft 59 is supported by a bearing bracket 60 depending from the side of the machine frame, and stepped pulleys 61 are fastened to said shaft adjacent the bracket 60. By means of the pulleys 61 and oppositely arranged stepped pulleys 62 and a drive pulley 64, the last two being lodated on a countershaft 63,4 the shaft 59 may he driven at any. desired speed. ,L v A handle 65 and a crank or the like are provided to raise and lower a connector 65a` the lower end of which is pivotally attached to a lever 6571 which operates the clutch collar 580. In this manner theshaft 58a 'canbe stopped and started, thus to co'troloscillation ofthe shaft 5 and the head 1.

Having described the principal parts of the improved machine necessary for an unin their adjusted positions. During this operation the headstock is stationary, the clutches in the driving means for the shaft 5 and also for the shaft 2 being at this time disengaged. Assuming a grinding Wheel 66 to have been mounted upon the shaft 25, the clutches are now engaged thus imparting to the Workpiece oscillation about the axis 4 and rotation about the axis 2 and the operator rotates the handle 14 which has the effect of moving the carrier ,11 and consequently the grinding wheel 66 mounted upon the shaft 25 longitudinally of the machine towards the Workpiece. During this forwardr movement of the slide the fluid supply of the Pelton wheel is automatically cut ol" and the arms 35 of the bell crank lever 36 contact with the pin 34 on the frame. therefore rocked upon its pivot 37 and through the connection 39 a downward movement is imparted to the free end of the arm 40 which causes the outer end of arm 43 to swing upwardly about the pivot 41- to raise the truing device 44 and associated `parts to an inoperative position.

.The longitudinal movement of the carrier 11 is continued' until the plane passing through the center of the grinding wheel and perpendicular to the axis contains the vertical axis 4 the carrier being stopped in .this posi- The bell crank lever 36 is tion by suitable stops thereon engaging co-opchine through the crank motion and connec` ingrod 16; this .movement continuing until the grinding' wheel just engages the work. VAt this point the clutch 220 in the driving mechanism 19 of the slide 15 is engaged and the slide 15 is driven by power until the grind- V- ing operation has been completed, when the clutch 22o is disengaged and the grinding wheel withdrawn clear ofthe work by ina nipulation of the handle 21. It will beninderstood that duringthe whole time .of engagement between the workpiece and the grinding Wheel the former is being oscillated continuoguslyfabout the axis 4 lthrough the driving connections/previously described. The throw of the crank mot-ion in the drive of the slide 15v determines of course the travel of the slide 15 andconsequently the maximum diameter of the raceway being ground.

As 'soon as the actual grinding operation has been completed, oscillation of the shaft 5 is stopped by manipulation of the handle 65, and the carrier 11 is moved longitudinally of the machine to withdraw the grinding wheel out of the work piece by manipulation ofthe handle 14.

During this movement of the carrier 11 the finger 30 rides up the inclined surface or cam 32 to rock the arm 31 and consequently the pawl or pawls 33 upwardly. The effect of this is to rotate the ratchet wheel 26 and shaft 27 causing movement of the slide 23 transversely of the machine and relatively to4 the slide 15. This movement is calculated to be equivalent to that required to compensate for the wear on the grinding wheel during the preceding grinding operation and in the machine shown is sutlicient also to permit an amount of material to be removed from the grinding wheel rby the truing device 44.

The truing device 44 is brought into operation during the movement of the carrier 11 v away from the head 1 by the arms 35 of the bell crank lever 36 moving out of contact with the projection 34 on the frameof the machine. It should be noted at this point that the arm 43, the Pelton wheel 48, oscillating member and the other parts of the truing mechanism, including the arm 40, are raised 'by the movement of the carrier 11 to carry the grinding wheel to grinding position,vso that their coiribined center of gravity hasmoved beyond the vertical plane of the pivotal axis 41.

Thus the weight of these parts, during the grinding operation, does not tend to move the carrier 11 to carry the wheel 66 out of grinding position, but rather tends to hold it there against the stops before mentioned. The subsequent movement of the carrier 11 to .carry the wheel out of position after a grinding operation causes positive movement of the truing mechanism in a clockwise direction, Fig. 4,. by reason of the fact that the pin 34 fits between the arms 35, 35. The pr0' vision of these two arms also insures vthe movement of the truing mechanism without shock,l and permits it to be lowered to the p0- sition shown in Fig. 4, where it rests against stops, not shown. 'At the same time the operation of the prime mover for oscillating the diamond truer, in this case the `Felton,

wheel 48, is initiated with the result that the diamond holder 45vis oscillated about its axis 47 throughl the connections and in the manner already described to true'the grinding wheel. The truing operation serves to maintain the cutting side of the grinding wheel at the moment of greatest advance of ,the slide 23, tangent to a' fixed vertical plane that yis parallel to the motion of the carrier 11, by reason of the fact that the whole truing mechanism is carried by the carrier 11 and slide 23 and is always s'cillated about the same axis 47. The compensating mechanism shown in Fig. 1 and already described which causes a slight movement of the` slide 23 on the slide-15 after each grinding operation serves to advance the grinding wheel towards the dressing device 44 by small increments for each grinding operation to insure contact between them. As the grinding wheel is a1- ways brought to the same lposition laterally of the machine by the connecting rod 16 and the actuating mechanism 19, uniform size of successive workpieces is insured.

During the truing operation the .previously ground workpiece is removed from the machine and a new one substituted therefor, the operation o-f the machine as already described being then repeated.

Owing to the fact that the slide is positively moved to eect grinding by means of a crank motion, a coarse feed is provided at,

the commencement of the grinding operation, and the feed is reduced gradually during the v g1" ding operation until at maximum stroke operating the slide 15, means is provided to urge the slide in one direction or the other to take up any such lost motion. This means is shown in Fig.'3 and comprises a shaft 71 which is given a torque by means of a spring 72, an arm 73 being fastened to the end of the shaft 71, and the upper end of said arm being attachedby a pin and fork connection 74 to the slide 15.

What I claim is 1. A grinding machine of the kind -described comprising a headstock fora workpiece, a rotatable shaft for a grinding wheel, means for moving said shaft endwise, to dispose said wheel in grinding position and a crank motion for. moving said shaft trans- 'versely to said endwise movement to bring' said grinding wheel into and out of grinding engagement with said workpiece.

2. A grinding machine of the kind described comprising a headstock `for a workpiece, a rotatable vshaft for a grinding wheel,Y

means for moving said shaft vendwise to dispose said wheel in grinding position, a crank motion for moving said shaft transversely to vthe said endwise movement to bring said grinding wheel into and out of grinding engagement with said workpiece, means for dressing said wheel, and means for compensating for wear on the grindingwheel and its reduction in diameter b dressing.

3. A grin in maciine of the kind described comprising a headstock for a work# piece, a rotatable shaft for a grinding wheel, means for moving said shaft endwise to dispose said Wheel in grinding position, a crank motion for moving said shaft transversely to said endwise movement to bring said grinding wheel into and out of grinding engagement with said workpiece, means for dressing said wheel, and means for automatically im parting a predetermined relative movement between said shaft and said headstock to compensate for wear of the grinding wheel and its reduction in diameter by dressing.

4. A grinding machine of the kind described comprising a headstock for a workpiece, a rotatable shaft for a grinding wheel, means for moving said shaft endvvise to dispose said wheel in grinding position, a crank motion for moving said shaft transversely to said endwise movement to bring said grinding wheel into grinding engagement with said workpiece, means brought into operation by said endwise movement in one direction .for truing the peripheral surface of said wheel, and Vmeans for imparting a predetermined transverse movement to said shaft to compensate for wear ofthe grinding wheel and its reduction in diameter by dressing.

5. 'A grinding machine of the kind described comprising an oscillatory headstock for a workpiece, a slide, a second slide mounted upon said first mentioned slide, a rotatable shaft for a grinding wheel mounted upon said second mentioned slide, means for moving said slides longitudinally of the machine tp dispose said wheel in grinding position, a crank motion for simultaneously moving said slides transversely to bring the grinding wheel into engagement with the workpiece, means for dressing said wheel, and means for moving one of said slides independently of the other to compensate for wear on the grinding wheel and its reduction in diameter by dressing.

6. A grinding machine comprising a headstock capable of oscillation about a vertical axis, a horizontally disposed rotatable shaft for a workpiece mounted upon said headstock, a horizontally disposed rotatable grind ing wheel shaft, a slide capable of movement i in a horizontal plane transversely of said machine and carrying said grinding wheel shaft, a second slide carrying said` first mentioned slide andalso capable of movement in a horizontal plane transverselyv of said machine, a carrier for said slides, means for moving said carrier longitudinally of said machine, a=Y

crank motion for moving ksaid slides transversely of the carrier to bring said grinding wheel into grinding engagement with the workpiece, means lfor dressing said wheel, and means for moving said first mentioned slide a predetermined distance relatively to said second mentioned slide during movement ,of said carrier away from said headstock to compensate for wear on said grinding wheel and itsreduction inl diameter by dressing.

7. A raceway grinding machine comprising a headstock capable of oscillation about a vertical axis and includinga horizontally disposed rotatable shaft to which the workpiece is adapted to be secured, a horizontally disposed rotatable grinding wheel shaft, means for moving said shaft longitudinally of the machine to carry the grinding wheel into and out of the workpiece, a crank motion for moving said shaft transversely of said machine to cause a grinding wheel mounted sthereon to move into grinding engagement withsaid workpiece, means 'for dressing said wheel, and means for moving said shaft transversely of the machine` as the grinding wheel is being moved away-.from the work to compensate for wear on the grinding wheel and its reduction in diameter by dressing.

8. A raeeway grinding machine of the class described comprising a horizontally disposed grindingwheel shaft, -a slide upon which said shaft is mounted', a second slide upon which said first mentioned slide is mounted, a carrier upon which both said slides are mounted, said carrier being movable longitudinally of the machine` for the purpose of moving said grinding wheel into and out of the workpiece, actuating means including a crank for i:fnovng said slides to; gether transversely o fthe machine to cause the grinding wheel to engage the workpiece, means for dressing said wheel and means for moving said first mentioned slide a predetermined distance transversely of the machine relatively to said second mentioned slide to compensate for wear of the grinding wheel and its reduction in diameter by dressing.

9. A raceway grinding machine of the class described comprising a horizontally disposed rotatable grinding wheel shaft, a slide upon which said shaft is mounted, a second slide upon which said first mentioned slide is mounted, `a carrier upon which both said slides are mounted, said carrier being movable longitudinally of the machine to carry the grinding wheel into` and out of the workpiece, actuating means including acrank for moving said slides together transversely of the machine to move the grinding wheel into and out of engagement withI the work, a shaft journalled in said .first mentioned slide and having tooth-like projections co-operating with a nut-like element associated with said second mentioned slide, a ratchet wheel mounted upon said shaft, a pawl rockably -upon said surface to cause rotation of said ratchet Wheel and movement of said firstmentioned slide relatively to said second mentioned slide when the carrier is moved longitudinally of said machine. l 10. AI raceway grinding machine of the class described comprising a horizontally disposed grinding wheel shaft, a slide upon which said shaft is mounted, a second slide upon which said first mentioned slide is mounted, a lcarrier upon which both said slides are mounted, said carrier being movyable longitudinally of the machine to carry the grinding wheel into and out of the workpiece, actuating means including a crank for moving said slides together transversely of the machine to bring the grinding wheel into and ont of grinding engagement with the wor`k,]means foi-moving a dressing device into position to. engage the peripheral surface of said Wheel on that movement of said carrier that carries the grinding wheel out of the workpiece, and means for moving said first-mentioned slide a predetermined dis# tance transversely of the machine relative to said second-mentioned slide, to compensate for wear of the grinding wheel and itsreduction in diameter `by dressing. i

11. A. raceway grinding machine of the class described, com rising a headstock for a workpiece, av rotata le shaft for a grinding wheel, a carrier for moving said shaft longitudinally of the mach-ine to carry a grinding wheelmounted thereon into and out of the workpiece, means for moving said shaft transversely of the machine to movev said grinding wheel into grinding engagement with the vworkpiece, an' oscillatable truing device pivotally mounted upon said carrier, a pin projecting from the frame of the machine, a bell crank lever pivotally mounted upon said carrier, said lever co-operating with said pin during movement of said carrier longitudinally of the machine to bring said truing device into and out of position to operate upon the peripheral surface of said grinding wheel and means operative on the longitudinal movementof said wheel away from the workpiece for transversely shifting its shaft a predetermined distance to compensate for wear on the grinding wheel and its reduction in diameter by said truing device.

12. A grinding machine of the kind described comprising an oscillatable headstock for a workpiece, a rotatable shaft for a grinding Wheel, means for moving said shaft endwise to dispose the wheel within the workpiece, and crank means, operating in timed u relation to the oscillation of the headstock, to move said shaft transversely, thereby to carry said grinding wheel into and out of grinding engagement with said' workpiece. In testimony whereof I have signe my name to this specification.

JOSEPH DYSON scAIrE. 

